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The present invention generally relates to devices, system, and methods for diagnosing and/or treating urinary incontinence. In an exemplary embodiment, the invention provides catheter-based pressure sensing systems for diagnosing female urinary incontinence, and in particular, provides systems for determining the relationship between urethral pressure and vesicle pressure in response to changes in abdominal pressure. Preferred aspects of the present invention relate to urethral catheter holder mechanisms.
Urinary incontinence arises in both men and women with varying degrees of severity, and from different causes. In men, the condition most frequently occurs as a result of prostatectomies which result in mechanical damage to the urethral sphincter. In women, the condition typically arises after pregnancy when musculoskeletal damage has occurred as a result of inelastic stretching of the structures which support the genitourinary tract. Specifically, pregnancy can result in inelastic stretching of the pelvic floor, the external sphincter, and the tissue structures which support the bladder and bladder neck region. In each of these cases, urinary leakage typically occurs when a patient""s abdominal pressure increases as a result of stress, e.g., coughing, sneezing, laughing, exercise, or the like.
Treatment of urinary incontinence can take a variety of forms. Most simply, the patient can wear absorptive devices or clothing, which is often sufficient for minor leakage events. Alternatively or additionally, patients may undertake exercises intended to strengthen the muscles in the pelvic region, or may attempt a behavior modification intended to reduce the incidence of urinary leakage.
In cases where such non-interventional approaches are inadequate or unacceptable, the patient may undergo surgery to correct the problem. A wide variety of procedures have been developed to correct urinary incontinence in women. Several of these procedures are specifically intended to support the bladder neck region. For example, sutures, straps or other artificial structures are often looped around the bladder neck and affixed to the pelvis, the endopelvic fascia, the ligaments which support the bladder, or the like. Other procedures involve surgical injections of bulking agents, inflatable balloons, or other elements to mechanically support the bladder neck.
In work related to the present invention, it has recently been proposed to treat incontinence by directing energy to a tissue structure comprising or supporting the patient""s urethra, bladder neck, or bladder. The energy can contract collagenous structures such as fascia, tendons, or the like, increasing the structural support of these natural support tissues. As described in PCT Application Serial Nos. 98/16754 and 97/20191, the full disclosures of which are incorporated herein by reference, the energy may be transmitted through an intermediate tissue, or by accessing the collagenous tissue surface in a minimally invasive manner.
Researchers have studied female urinary incontinence by evaluating the relationship between a patient""s urethral pressure and her vesicle (i.e.:, bladder) pressure. In an article by Kim et al., The Vesico-Urethral Pressuregram Analysis of Urethral Function Under Stress, Journal of Biomechanics, Vol. 30, page 19 (1997), proposed a method for analyzing the interaction between the vesicle pressure and urethral pressure to assess urinary stress incontinence. Both urethral pressure and vesicle pressure will change in response to changes in abdominal pressure. However, the urethral and vesicle pressures may change at different rates as the abdominal pressure changes. Incontinence may occur when the vesicle pressure exceeds the urethral pressure. Hence, incontinence can be studied by producing a pressuregram showing the relationship between the urethral pressure and the vesicle pressure of the patient during abdominal pressure pulses.
A patient""s vesicle and urethral pressures can be measured by introducing a catheter into the urethra and positioning pressure sensors of the catheter at the desired measurement sites in the urethra and/or bladder. The measurements of the patient""s vesicle and urethral pressures are preferably taken simultaneously during changes in abdominal pressures.
Unfortunately, simultaneous pressure measurements can be difficult to obtain using presently available pressure-sensing catheters. Hence, existing systems are not well suited for diagnosing urinary incontinence of a particular patient. Similarly, while the recently proposed tissue contraction therapies offer great promise for treatment of urinary stress incontinence, proper treatment to enhance elongated or weak support structures of a particular patient could benefit significantly from improved techniques for diagnosing urinary incontinence.
In light of the above, it would be desirable to provide improved devices, systems, and methods for diagnosing and/or treating urinary incontinence.
The present invention generally provides improved devices, systems, and methods for diagnosing and/or treating urinary incontinence. The invention provides pressure-sensing catheter systems which can accurately and reliably monitor both a vesicle pressure and a maximum urethral pressure of a patient during an abdominal pressure pulse so as to determine relationships between these pressures. Work in connection with the invention has shown that diagnostic urethral pressure measurements during a pressure pulse are sensitive to loss of alignment between the pressure sensor and the target pressure location. Advantageously, alignment between, for example, the location of maximum urethral pressure and a pressure sensor of a catheter can be maintained using an anchoring structure having a surface which engages a tissue surface along the bladder neck, urethra, or external meatus (the tissue structure adjacent the urethral opening). These tissues generally moves with the urethra during abdominal pressure pulses, so that the anchoring structure will often move the pressure sensor when an abdominal pressure pulse is induced. The invention allows a reliable, accurate pressuregram to be generated, the pressuregram graphically showing an increase in urethral pressure relative to an increase in vesicle pressure. This pressuregram will ideally be displayed in real time to a system operator adjacent the patient, and may provide a quantitative and/or qualitative diagnostic output allowing selective remodeling of the patient""s support structure so that the incontinence is inhibited.
In a first aspect, the invention provides an apparatus for evaluating urinary incontinence of a patient. The patient has a urethra extending from a bladder to a urethral opening, with a maximum urethral pressure disposed between the bladder and opening. The system comprises a pressure-sensing system including an elongate body having a proximal end and a distal end. A vesicle pressure sensor is disposed adjacent the distal end for measuring fluid pressure within the bladder. At least one urethral pressure sensor is disposed proximally of the vesicle pressure sensor for measuring urethral pressure. An anchoring structure is disposed along the elongate body. The anchoring structure is adapted to engage a tissue surface adjacent the urethra so as to maintain alignment between the urethral pressure sensor and the maximum urethral pressure when a pressure pulse moves the urethra. A processor is coupled to the pressure-sensing system. The processor calculates a relationship between the urethral pressure and the vesicle pressure.
Typically, the calculated relationship will comprise a pressuregram which is shown on a display in real time to a system operator disposed adjacent the patient. The pressuregram will typically include a slope defined by an increase of the measured vesicle pressure relative to an increase of the measured urethral pressure. Such pressuregram may be calculated from a plurality of pressure pulses, and will typically be independent of time. The pressuregram may be displayed in a variety of formats, including plotting simultaneous pressure data pairs taken simultaneously in the urethra and the bladder, with vesicular pressure along a horizontal axis and urethral pressure along a vertical axis or vice-versa.
The anchoring structure will often comprise a radially expandable structure, the expandable structure preferably having at least one channel allowing free transmission of urine through the urethra when expanded. Suitable expandable structures include balloons having multiple lobes defining the channel therebetween. The expandable structure may expand within the urethral passage to engage the surrounding tissues, or may be inserted and expanded beyond the urethra so that a proximally oriented surface of the expandable structure engages the bladder. In many embodiments, a distally oriented surface will be positionable along the elongate body to engage an external meatus so as to substantially affix the urethral pressure sensor relative to the maximum urethral pressure location.
The anchoring structure may comprise at least one vacuum port disposed along the elongate body and oriented to engage a tissue along the urethra. When a vacuum is applied to the vacuum port, the vacuum port can safely secure the urethral pressure sensor at the desired position within the urethra. In some embodiments, a plurality of urethral pressure sensors may be distributed axially so as to reduce sensitivity of the pressure sensor system to movement relative to the surrounding urethra.
The present invention also provides a urethral catheter holder which is adapted to support a pressure-sensing catheter such that the catheter can be positioned along the patient""s urethra. The holder can generally maintain alignment with a maximum urethral pressure by allowing the catheter to move in response to urethral movement such that a pressure-sensing transducer disposed on the catheter does not move relative to the urethra when the patient coughs.
In a preferred aspect of the present invention, the urethral catheter holder comprises a supporting base, which is adapted to register against the labia of the patient; a suspension housing mounted to the supporting base; a catheter securement device, (which is adapted to move within the suspension housing when the patient coughs such that the catheter moves with the urethra); and a biasing device. In preferred aspects, the catheter securement device comprises a catheter guide which is adapted to contact against the external meatus of the patient""s urethra. The biasing device operates to provide a preloading force on the catheter guide, thereby holding the catheter guide against the external meatus of the patient""s urethra such that the catheter securement device moves with the movement of the urethra. Additionally, the biasing device operates to push the catheter securement device against the supporting base, thereby minimizing unwanted motion of the catheter securement device within the suspension housing.
The catheter securement device is adapted to support the catheter in a manner such that the catheter moves in response to movement of the urethra, with the catheter remaining in generally the same position relative to the surrounding urethra when the patient coughs. In a preferred aspect, the catheter securement device comprises a torroidal balloon, a generally ring-shaped balloon support mount surrounding the torroidal balloon and a pneumatic or hydraulic pressure tube for inflating or deflating the torroidal balloon. The catheter passes longitudinally through the catheter holder and is received through the orifice defined by the torroidal balloon. Inflation of the torroidal balloon will cause it to expand radially inwardly such that it""s central orifice contracts, thereby gently pushing against the sides of the catheter.
In other preferred aspects of the invention, the catheter securement device comprises a mechanical clamp which is mounted to move longitudinally within the suspension housing.
Optionally, the present urethral catheter holder may also comprise a pair of leg straps, which can be wrapped around the patient""s thighs, (or a stretchable undergarment with leg straps attachable thereto), such that the supporting base of the catheter holder can be held at a generally fixed position against the labia of the patient. An advantage of such leg straps is that pressure measurements can then be taken easily with the patient in different positions, including supine and sitting. An additional advantage of the present system is that it allows hands-free operation for the clinician.
In another aspect, the invention provides a data system for use with a mechanism for diagnosing urinary incontinence of a patient. The mechanism produces a pressuregram indicating a pressuregram slope defined by a change of urethral pressure of the patient relative to a change of vesicle pressure of the patient. The vesicle and urethral pressures are measured with a catheter system having a proximal end and a distal end. The data system comprises a processor coupled to the catheter for receiving a vesicle pressure signal and urethral pressure signal. The processor generates a pressuregram dataset in real time. At least in part from the vesicle and urethral pressure signals. A display is coupled to the processor so as to generate a real time image of the pressuregram from the pressuregram dataset. The display is visible from adjacent the proximal end of the catheter.
Generally, a soft tissue of the patient moves with the urethra during a pelvic pressure pulse. Suitable pressure pulses can be induced by having the patient cough, by having the patient perform the Valsalva maneuver, by pushing manually or with an impulse device against the abdomen, or the like. To accommodate the resulting tissue movement, the system will often include a catheter positioning surface attached to the catheter. The catheter positioning surface will be adapted to engage the soft tissue so as to inhibit movement of the catheter within the urethra. In some embodiments, the positioning surface may be insertable along at least a portion of the urethra. Such positioning surface include high friction outer catheter surfaces, surfaces surrounding vacuum ports, atraumatic balloons, and the like. Optionally, some mechanism for facilitating insertion and removal of the catheter may be provided, such as a low friction interface sheath, or the like.
Alternative embodiments may include positioning surfaces which are larger in cross-section than the catheter so as to engage a soft tissue beyond the urethra, such as an external meatus, bladder, or the like, with such large positioning surfaces often being adjustably affixable along an axis of the catheter to facilitate positioning of the urethral pressure sensor at the point of maximum urethral pressure. In such embodiments, a biasing mechanism will often support the positioning surface against the external meatus, the support often reacting against a reaction support such as leg straps, a garment, or the like. The biasing mechanism will preferably allow at least about 2 cm of movement of the external meatus and catheter without altering the alignment of the urethral pressure sensor.
The processor will preferably selectably display one or more pressure pulses, and will ideally be selectably capable of refreshing the display between pressure pulses. An exemplary processor extrapolates an equilibrium pressure (above which the vesicle pressure exceeds the urethral pressure) using a curve approximation of the pressuregram.
In yet another aspect, the invention provides a system for treatment of urinary stress incontinence of a patient. The patient has a tissue comprising or supporting the urethra, the bladder neck, or the bladder. The system comprises a diagnostic system including a urethral pressure sensor, a bladder pressure sensor, and a processor coupled to the sensors. The processor generates an output indicating a desired remodeling of the tissue of the patient. A probe has an energy-transmitting element that controllably delivers energy to the tissue so as to effect the desire remodeling such that incontinence is inhibited.
In some embodiments, the probe may be used to controllably deliver the energy in response to the output of the processor. Optionally, the processor may be coupled to the probe and may provide an energy signal to the probe so as to control the delivered energy.
In another method aspect, the invention provides a method for treating urinary stress incontinence of a patient. The method comprises sensing a bladder pressure and a urethral pressure. A desired remodeling of a tissue comprising or supporting a urethra, a bladder neck, and/or a bladder of the patient is determined from the bladder pressure and the urethral pressure. The desired remodeling of the tissue is effected so that incontinence is inhibited.
Typically, a pressure pulse will be generated during the sensing step. The pressure pulse may, in some embodiments, be generated after effecting partial remodeling of the tissue for use as feedback during the remodeling step.
In yet another method aspect, the invention provides a method for treatment of urinary stress incontinence of a patient. A pressuregram of the patient indicates a urethral pressure of the patient which differs from a vesicle pressure of the patient by a continence margin. The pressuregram has a pressuregram slope defined as a change of the vesicle pressure relative to a change of the urethral pressure. The pressuregram slope is such that the vesicle pressure will exceed the urethral pressure of the patient above an equilibrium pressure. The method comprises determining a desired change in a support tissue comprising or supporting the urethra based at least in part on the equilibrium pressure, the continence margin, and/or the pressuregram slope. The support tissue is remodeled per the desired change.
The remodeling step may comprise directing energy into the support tissue so as to contract the support tissue. Often times, a plurality of pressuregrams will be taken with the patient in different positions, such as standing, sitting, supine, and the like, for determining the desired change.
In yet another aspect, the invention provides a system for evaluating urinary incontinence. The system comprises a body having a proximal end, a distal end, and a cross-section suitable for insertion into a urethra. A pressure sensor is disposed along the body for measuring urethral pressure, and a position sensing system or means is couplable to the body to measure an axial position of the pressure sensor within the urethra.